Certification by means of fraudulent representations constitutes a High Crime punishable the same as any form of perjury, subversion, impersonation, and more. Furthermore, a number of U.S. Senators, Representatives, and justices may be impeached and convicted for their own roles in the fraud.
In order to prove any thing “fraudulent”, one must prove that someone intended to mislead.
I’m no lawyer, but I don’t think you can impeach Congressmen and Senators. They can be Censored, but impeachment is for Pres and VP. They can be prosecuted if they allow it themselves. A Congresscritter cannot even be arrested while in session. If Boehner or Pelosi doesn’t allow it, what then?